The proposed research will build, refine, and test in operational use, a set of software tools designed to help support, maintain, and iteratively revalidate computer-based clinical guidelines as they evolve over time. The project will focus on the domain of childhood immunization, and will build upon IMM/Serve, a childhood immunization forecasting program that takes as input a child's immunization history, and produces recommendations as to which vaccinations are due and which vaccinations should be scheduled next. The effort required to modify and validate such a program as the clinical field evolves over time is a challenging task. It will be extremely important to have a robust set of tools to assist in this process. Partial prototype versions of certain of these tools already exist. 1. The project will refine and extend computer-based tools for immunization knowledge maintenance. These tools will include: a) IMM/Def, a program which automatically generates the rule-based logic for the most complex portion ("kernel") of IMM/Serve's knowledge, and b) IMM/Test, a program which automatically generates a set of test cases to help test the kernel logic. The project will also develop an organized set of strategies for immunization test case generation, and implement those strategies in the refined version of IMM/Test. 2. The project will build a Web site to support immunization knowledge maintenance. 3. The project will keep a detailed record of all modifications and customization of the knowledge, and will represent all the variations of the knowledge using a standardized format such as GLIF, the Guideline Interchange Format being developed as a standard for exchanging guidelines between sites. 4. The project will link IMM/Serve to a database designed to hold IMM/Serve's analysis of a set of cases, so that the resulting package can be used as a tool to perform compliance assessment. 5. A set of evaluation studies will be carried out to help assess the efficacy of the tools and to help improve their functionality.